Lack of clinical usefulness of interleukin-6 in long-term follow-up of acutely decompensated heart failure

Ruiz-Ruiz FJ, Ruiz-Laiglesia F, Lasierra-Diaz P, Samperiz-Legarre P, Morales-Rull JL, Sánchez-Marteles M, Amores M, Perez-Calvo JI
Correspondence: Dr Francisco J Ruiz-Ruiz, fruiz@comz.org

ABSTRACT
Introduction Interleukin-6 (IL-6) has been identified as a predictor of death, new heart failure (HF) episodes and need for heart transplantation in patients with advanced HF. The aim of this study was to examine the relationship between plasma IL-6 levels in patients with decompensated HF and either survival or new admissions due to HF.
Methods We studied 111 patients admitted due to decompensated HF. Long-term survival was assessed from the day of admission to the hospital to the day of death or new admissions due to HF.
Results The mean IL-6 concentration was 90 +/- 115 pg/ml (range 1.5-743 pg/ml). There were no differences in IL-6 concentration with regard to age, gender and cause of HF. At the end of follow-up period, 22 patients (20 percent) had died due to causes related to HF and 54 patients (48 percent) had been readmitted to the hospital due to new HF episodes. Using regression analyses, serum IL-6 levels were not identified as a prognostic factor. Systolic dysfunction, previous diagnosis of HF and diabetes mellitus were independent predictors of death.
Conclusion These findings suggest that a single measurement of serum IL-6 in patients with decompensated HF lacks clinical usefulness in long-term follow-up.

Keywords: cytokines, decompensated heart failure, heart failure prognosis, interleukin-6
Singapore Med J 2007; 48(6): 532–536